1. Field of the Invention
The present invention relates to a method for gas metal arc welding of steel containing 0.005-0.06%C by weight.
2. Description of the Prior Art
Quite recently, with the remarkable progress of the controlled rolling process, there is a general tendency for steel products, including those for making a large diameter line pipe, to be produced with a very low percentage of carbon by weight so as to give these products improved weldability and to reduce the cost of production.
It has been generally considered that the susceptibility of such very low carbon steels to high temperature cracking of the weld metal is generally low. However, although the reduction of the carbon content of the weld metal has generally proved to be beneficial in the welding of steel from the viewpoint of preventing the high temperature cracking of the weld metal, an extensive investigation conducted by the present inventors shows that high temperature cracking tends to occur despite a sufficiently low content of carbon in the weld metal when gas metal arc welding of very low carbon steels containing less than 0.06%C weight is carried out using known welding materials.